THE interaction between human and non-human animals fascinates everyone from anthropologists to the average pet owner. It even has a name – anthrozoology – as biologist John Bradshaw reminds us in the subtitle of his new book, The Animals Among Us.

(Buy from *)

As Bradshaw points out, for humans to consistently live with and nurture animals is a most unusual trait in nature. So a strong, fact-based discussion of how and why we do this and its effects should be eye-opening, engaging and thought-provoking.

Animals ticks some of those boxes, but by no means all. Bradshaw knows how to produce a well-written and accessible tome. A veteran of popular books about the lives and habits of cats and dogs, he focuses most on the ubiquity of people keeping animals, today and over the past few hundred years, and specifically on pets.

As he rightly observes, the practice of taking in and raising young animals is widespread among humans, little influenced by geography or culture. Oddly, though, he seems shocked that this intimacy can extend to the breast-feeding of young animals, domestic or wild. This isn’t rare in many modern cultures and probably wasn’t in the past. Calling groups who engage in the behaviour “surviving Palaeolithic peoples”, as he does, is inaccurate and culturally insensitive.

Bradshaw suggests that the inclusion of animals as intimate members of the family probably explains the long-term connection behind the genetic and behavioural alterations we now see in domestic species.

Even so, domestication is a less common outcome of keeping animals than we might expect, given that even the most generous list would only include 20 or so domesticated species. Many more have spent at least some time in captivity, so it is well worth asking why so many species that have lived intimately with us haven’t been domesticated.

“It’s worth asking why so many species that have lived with us have never been domesticated”

For Bradshaw, the answer lies partly in the kinds of societies that kept animals. He reasons that in egalitarian, hunter-gatherer societies, animals could be brought into the family and kept temporarily before being eaten or sacrificed, or perhaps kept more permanently. As these societies gave way to stratified, agricultural societies, the animals that were kept depended on their benefit to the household at that time.

During this period, keeping domesticated animals became a status symbol – leading to the rise of pets. Part of their appeal, says Bradshaw (on little evidence), is an atavistic liking of stroking and grooming the fur of another, which he believes played a role in our ancestral, furry past (we lost most of it some 1.6 million years ago) as it does now among non-human primates.

But do we really keep pets so we can stroke them? Stroking a pet has been shown to raise circulating levels of the “feel-good” hormone oxytocin in both participants. Why don’t we keep pets that stroke us back?

Bradshaw’s main interest seems to lie in the period between medieval times and the 20th century, which makes this part of the book especially lively and informative. The Victorian era saw the rise of keeping pets and the display of animals with particular colours or shapes to confer status. This was also the time that breed societies and animal shows were founded, and there was a general growth of desirable “types” among all kinds of domestic species, particularly in the UK.

Bradshaw discusses this period at length, dwelling on the transformation of pets from working animals to “members of the family” as the attributes of domesticated species became a reflection of social standing. And in agricultural Britain, having good livestock or animals was of tremendous importance to their owners’ success.

Modern life generally is now very different, more industrialised and urban, but the animals we live with continue to carry great social and symbolic weight. According to Bradshaw, Westerners have reached the third phase of living with animals, where the practice is so common that it is universally accepted.

In fact, pets are increasingly seen as offering us tangible benefits – as therapy animals, assistants to people who are blind or disabled, and companions to those who are socially isolated. Pets are often said to provide distinct health benefits to those with mental, social or physical problems, though Bradshaw points out that the evidence isn’t as strong as the claims for it.

In one of the best and most thought-provoking parts of his book, Bradshaw dissects the practice of anthropomorphism as a typically human attempt to understand the animals with which we live so intimately. He raises important questions about the greater significance of keeping pets and their benefits. For example, is assigning human characteristics to another species really key to the close emotional and family-type relationships many humans form with their pets? Does anthropomorphism balance out the energetic and economic costs of pets in the modern world?

I take a very different view: anthropomorphism is as much a barrier to domestication and close relationships with animals as it is a boon. My view of domestication is that humans and the species that find it worthwhile negotiate a common language – a world view that is neither human nor animal.

Even very clever dogs can’t understand more than a few hundred words, and they don’t share our framework for perception. Simply put, we perceive very little of what a dog does: for example, we are nearly scent-blind. Equally, dogs don’t perceive as we do nor think about things the way we do. For true cooperation and communication, dogs and humans must each alter their “language” so they understand each other. This process is active, a choice as well as an evolutionary adaptation. Casting a dog’s actions in human terms is tempting for a human, but doesn’t further the exchange of ideas by much.

At the end of the book, Bradshaw brings it all together by proposing four explanations of the human propensity for keeping pets. First, he reminds us of the idea that the loss of most of our body hair left us with a liking for stroking and grooming.

His second concerns the evolution of the human brain in a way that resulted in us being able to analyse animal behaviour and develop the capacity for anthropomorphism, leading to better animal-keeping.

His third explanation is that young women who were good at caring for animals may have been assumed to become better mothers, making them preferred as brides. This could cause a spread of genes that would make many people good with animals.

“Does anthropomorphism balance out the energetic and economic costs of pets in the modern world?”

And last, he hypothesises that the rise of taboos against eating and killing personal (owned) animals enabled long-term pet-keeping, which is necessary for domestication. I am sceptical about this scenario since, again, little hard evidence supports it or links each stage to the next.

I wish Bradshaw had included more evidence on the much-researched origin of dogs. Surely the first instance of domestication in the world, of wolves into dogs, should play a crucial role in our understanding of the phenomenon of living with and domesticating animals?

But Bradshaw doesn’t dwell on the ongoing and exciting work investigating the genetic, morphological and behavioural differences among wolves and some dogs, including ancient fossil specimens. He neglects research on basal or genetically ancestral breeds, such as basenjis, dingoes and the recently rediscovered New Guinea mountain dogs. These species should tell us a lot about the sort of canid that was originally domesticated.

Bradshaw also gives short shrift to work by leading scholars, such as Mietje Germonpré at the Royal Belgian Institute of Natural Sciences and Melinda Zeder at the Smithsonian Institution in Washington DC. And he often supports his arguments with out-of-date contributions to the field or articles in popular magazines or newspapers rather than peer-reviewed journals.

This means that he gives too much credence to ideas that haven’t been rigorously tested or that have been overturned by later studies. While there are many good things in his book, understanding and interpreting our tendency to live with animals and its impact is an important and vibrant field that deserves a fuller presentation than Bradshaw offers here.

This article appeared in print under the headline “Creature comforts”

(*When you buy through links on this page we may earn a small commission, but this plays no role in what we review or our opinion of it.)

Based on the fossil record, most palaeontologists have assumed that the burst
of evolutionary activity that gave rise to the modern orders of mammals and
birds took place between 50 and 60 million years ago. The surviving vertebrates
were thought to have diversified to fill the ecological niches vacated by the
dinosaurs a few million years before. But researchers in the US now argue that
this diversification took place much earlier, and was driven by tectonic
activity and geographical isolation, not mass extinction.

Blair Hedges, Patrick Parker and Sudhir Kumar of the Pennsylvania State
University, working with Charles Sibley, a retired biologist formerly at Yale
University, have completed an analysis of 79 genes in 16 orders of mammals and
17 orders of birds—the largest ever study of its type. “We analysed all
the relevant information in the genetic databases,” says Hedges.

The trick with using genes to trace evolutionary history is to find a valid
way of translating the number of molecular differences between any pair of
living forms into the number of years since their last common ancestor was
alive.

Genetic changes accumulate over time, but evolutionary biologists need a
known calibration point in time to transform the number of mutations into a rate
of genetic change. The problem is that not all genes mutate at constant rates,
and not all dates in the fossil record are known with certainty.

For each pair of orders within the mammals and the birds, Hedges and his team
counted the mutations accumulated in each lineage since the last ancestor shared
by both. If both lineages had accumulated roughly equal numbers of mutations,
the researchers assumed the gene in question had evolved at a relatively
constant rate.

Unequal numbers were taken to mean fluctuating rates of mutational change,
making that gene a poor molecular time-keeper. The researchers were also able to
select a reliable calibration point from the fossil record: the divergence of
the reptilian ancestors of birds from the ancestors of mammals some 310 million
years ago.

In this week’s issue of Nature (vol 381, p 226) Hedges and his
colleagues say that data from the constant-rate genes give dates for the
diversification of modern orders of birds and mammals between 50 and 90 per cent
earlier than previously thought.

If so, the fossil record of the early part of avian and mammalian evolution
must be terribly poor. “I find it hard to believe that there are 40 or 50
million years of evolution that leave no trace at all,” says Kenneth Rose, a
palaeontologist at the Johns Hopkins Medical School in Baltimore.

But other palaeontologists argue that major gaps in the fossil record are not
unknown. In 1993, for instance, Robert Martin of the University of Zurich
calculated that the 200 living primate species must have been preceded by 6500
extinct primates—assuming that mammal species survive on average for 1
million years.

Martin pointed out that only 3.8 per cent of these species have been
discovered, and concluded that the first primates probably emerged about 80
million years ago, some 25 million years before the earliest known primate
fossil. Martin says he is “as pleased as Punch” that the new analysis has backed
his conclusions.